Computer Tips - Programming, Cybersecurity and Tech Tutorials

FFmpeg: FFmpeg is a free software project that produces libraries and programs for handling multimedia data. Download link: https://ffmpeg.org/download.html Format Factory: FormatFactory is an ad-supported freeware multimedia converter that can convert video, audio, and picture files. It is also capable of ripping DVDs and CDs to other file formats, as well as creating .iso images. It can also join multiple video files together into one. Download link: http://www.pcfreetime.com/formatfactory/feature.php?language=en How to extract audio from video using FFmpeg: If you just want to copy the audio stream without re-encoding just do: ffmpeg -i input-video.avi -vn -acodec copy output-audio.aac -vn is no video. -acodec copy says use the same audio stream that's already in there. Read the output to see what codec it is, to set the right filename extension.

SQLite is an in-process library that implements a self-contained, serverless, zero-configuration, transactional SQL database engine. The code for SQLite is in the public domain and is thus free for use for any purpose, commercial or private. SQLite is the most widely deployed database in the world with more applications than we can count, including several high-profile projects. [ https://www.sqlite.org/about.html ] Following program demonstrates how to Create a new SQLite database, how to connect to a database with credentials, how to create a table, how to insert values and how to select values. #!/usr/bin/perl use DBI; use strict; use warnings; my $dsn = "DBI:SQLite:test.db"; my $userid = ""; my $password = ""; my $dbh = DBI->connect($dsn, $userid, $password, { RaiseError => 1, AutoCommit => 0})    or die $DBI::errstr; print "Opened database successfully\n";

Networkx: NetworkX is a Python package for the creation, manipulation, and study of the structure, dynamics, and functions of complex networks. URL: https://networkx.github.io/ Code: import networkx as nx import matplotlib.pyplot as plt G=nx.Graph() color_map = ['blue','green','red'] G.add_nodes_from([1,10]) G.add_edge(1,2) G.add_edge(1,3) G.add_edge(4,3) G.add_edge(5,3) G.add_edge(6,8) G.add_edge(7,9) G.add_edge(8,7) G.add_edge(9,6) G.add_edge(10,5) G.add_edge(1,4) nx.draw(G,node_color = color_map,with_labels = True) plt.show() Output: This example draws a colored node graph in Python with NetworkX and Matplotlib. NetworkX builds and analyzes graphs, and a color map assigns a color to each node before drawing. Visualizing a graph helps you see structure such as clusters and hubs. NetworkX also offers many algorithms for paths, centrality, and connectivity on the same graph object.

Perl script to fetch live jobs' status from Jenkins server and generate and display HTML dashboard from it. use strict; use warnings; use autodie; use REST::Client; use MIME::Base64; use JSON; my $api_proto = 'http';               #HTTP/HTTPS my $api_url = 'localhost';       #Server IP my $api_port = '8080';                #Port number my $api_user = 'admin';           #Jenkins account username my $api_pass = 'password';          #Jenkins account password my $client = REST::Client->new();    #Perl Rest Client Object $client->addHeader('Authorization', 'Basic '.encode_base64($api_user . ':' . $api_pass)); $client->GET($api_proto.'://'.$api_url.':'.$api_port.'/api/json?tree=jobs[name,color,url]'); my $html = ""; $html = $ht...

DICOM: Digital Imaging and Communications in Medicine (DICOM) is a standard for storing and transmitting medical images. It includes a file format definition and a network communications protocol. PNG: PNG (pronounced ping as in ping-pong; for Portable Network Graphics) is a file format for image compression that, in time, is expected to replace the Graphics Interchange Format (GIF) that is widely used on today's Internet. Portable Network Graphics (PNG /ˈpɪŋ/) is a raster graphics file format that supports lossless data compression. PNG was created as an improved, non-patented replacement for Graphics Interchange Format (GIF), and is the most widely used lossless image compression format on the Internet. Prerequisites: You need to install following python packages: pydicom, pylab, pypng To install these modules you can type following commands in console: pip install pydicom pip install pylab pip install pypng

In case you are a newbie with Jenkins read through this article: http://com.puter.tips/2017/09/getting-up-and-running-with-jenkins.html Build Jenkins Job Remotely I have found two ways in which you can trigger a build on job remotely via scripting. Both methods are simple HTTP Get/Post requests, nothing fancy here. Along with these Requests we need to pass login credentials. Method 0: No protection enabled => This is the case when you are in a secure environment and have disabled all additional protection mechanism like CSRF (Method 1) and Authentication Token (Method 2). If this is the case then you can simply trigger a HTTP Request like this: 'http://username:password@jenkins_url:port/job/job_name/build' e.g. http://admin:pass@localhost:8080/job/job1/build

Powershell: $acctname = "admin" $password = "password" $server = "localhost" $port = "8080" $jobName = "test02" $jobToken = "test02_authentication_token" $params = @{uri = "http://${server}:${port}/job/${jobName}/build?token=${jobToken}";             Method = 'Get';             Headers = @{Authorization = 'Basic ' + [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes("$(${acctname}):$(${password})"));}} Invoke-RestMethod @params

Python: import requests api_proto = 'http' api_url = 'localhost' api_port = '8080' api_job = 'test01' api_user = 'admin' api_pass = 'password' api_crumb = requests.get(api_proto + '://' + api_user + ':' + api_pass + '@' + api_url + ':' + api_port + '/crumbIssuer/api/json') if api_crumb.status_code == 200 :     api_crumb = api_crumb.json()['crumb'] resp = requests.post(api_proto + '://' + api_url + ':' + api_port + '/job/' + api_job + '/build', auth=(api_user, api_pass), headers={"Jenkins-Crumb":api_crumb}) if resp.status_code == 201:     print(api_job + ' was triggered successfuly..')

Error: Traceback (most recent call last):   File "C:\Users\310211146\AppData\Local\Continuum\Anaconda3\lib\site-packages\requests\api.py", line 110, in post     return request('post', url, data=data, json=json, **kwargs)   File "C:\Users\310211146\AppData\Local\Continuum\Anaconda3\lib\site-packages\requests\api.py", line 56, in request     return session.request(method=method, url=url, **kwargs)   File "C:\Users\310211146\AppData\Local\Continuum\Anaconda3\lib\site-packages\requests\sessions.py", line 475, in request     resp = self.send(prep, **send_kwargs)   File "C:\Users\310211146\AppData\Local\Continuum\Anaconda3\lib\site-packages\requests\sessions.py", line 590, in send     adapter = self.get_adapter(url=request.url)   File "C:\Users\310211146\AppData\Local\Continuum\Anaconda3\lib\site-packages\requests\sessions.py", line 672, in get_adapter     raise InvalidSchema(...

Jenkins: The leading open source automation server, Jenkins provides hundreds of plugins to support building, deploying and automating any project. Jenkins is a Continuous Integration server. Basically Continuous Integration is the practice of running your tests on a non-developer machine automatically every-time someone pushes new code into the source repository. Prerequisites: Java Development Kit (JDK) Java Run-time Environment (JRE) To install JDK go to http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html To install JRE go to http://www.oracle.com/technetwork/java/javase/downloads/jre8-downloads-2133155.html

Code: mydf <- data.frame(Key=c('a','b','c','d','a','a','a','a','b','c','d','c','c','d','b','b','a'), Values=c(4,6,3,4,5,6,2,1,3,4,5,6,4,2,4,5,6))                 mydf_keys <- unique(mydf$Key) mydf_vals <- c(nrow(mydf_keys)) for (i in mydf_keys) {     mydf_vals <- c(mydf_vals, nrow(mydf[mydf$Key %in% i, ])) } #mydf_count gives count of items i.e. how many times they appear mydf_count <- data.frame(item=mydf_keys, count=mydf_vals) print(mydf_count) #mydf_sum gives sum of values of items in the column you specify mydf_sum <- setNames(aggregate(mydf$Values, by = list(item=mydf$Key), FUN = sum, na.rm = TRUE), c('item', 'sum')) print(mydf_sum) Output: If you have a better approach for this then please share in the comments below or email me. :) This R example groups rows by a key column and comput...

Microsoft R Open is Multi-core environment developed on Core R. Microsoft R Open (MRO), formerly known as Revolution R Open (RRO), is the enhanced distribution of R from Microsoft Corporation. It is a complete open source platform for statistical analysis and data science. Microsoft R Open 3.4.1 is coming September 11th. MRO comes with Microsoft R Open GUI and you can also use it in RStudio IDE. But in case you want to run it from command prompt, it is pretty easy. First you need to set Path in environment variable. For 32-bit version path would be like: C:\Program Files\Microsoft\R Open\R-3.4.0\bin For 64-bit version path would be like: C:\Program Files\Microsoft\R Open\R-3.4.0\bin\x64 Now save it and restart command prompt if already open or open a new command prompt window. Type command "where rscript" and check whether it returns a correct path. Now you can type command "rscript your_script.r" and it will get executed. No...

Xiaomi Mi A1 The Xiaomi Mi A1 is a dual-SIM (Nano-SIM) smartphone that runs Android 7.1.2 Nougat. It features a 5.5-inch full-HD (1080x1920 pixels) display. It is powered by an octa-core Qualcomm Snapdragon 625 SoC coupled with 4GB of RAM. In terms of optics, the dual rear camera setup of the Xiaomi Mi A1 bears two 12-megapixel sensors, with one featuring a wide-angle lens with a 1.25-micron pixel sensor and f/2.2 aperture, and the other sporting a telephoto lens, 1-micron pixel sensor, an f/2.6 aperture, and capable of delivering 2x optical zoom. The smartphone bears a 5-megapixel front camera with a real-time beautification mode. The Xiaomi Mi A1 comes with 64GB of inbuilt storage, which is expandable via microSD card (up to 128GB) in a hybrid dual-SIM configuration. It houses a 3080mAh battery. Motorola Moto G5S Plus The dual-SIM (Nano) Moto G5S Plus runs Android 7.1 Nougat out of the box, and it sports a 5.5-inch full-HD (1080x1920 pixels) IPS LCD display. It is...

Subroutines:- 1. Retrieving arguments to a subroutine with shift: A subroutine's arguments come in via the special @_ array. The shift without an argument defaults to @_ .     sub volume {         my $height = shift ;         my $width = shift ;         my $depth = shift ;         return $height * $width * $depth ;     }

C parameter passing:- 1. Pass by Value: - The value of a variable is sent to function. - The actual parameter cannot be changed by function. - Duplicate Copy of Original Parameter is Passed. - No effect on Original Parameter after modifying parameter in function. # include < stdio.h > void interchange ( int number1 , int number2 ) { int temp ; temp = number1 ; number1 = number2 ; number2 = temp ; } int main ( ) { int num1 = 50 , num2 = 70 ; interchange ( num1 , num2 ) ; printf ( " \n Number 1 : %d " , num1 ) ; printf ( " \n Number 2 : %d " , num2 ) ; return ( 0 ) ; }